I’ve used the Mars Coat King sized for Cairn terriers for at least two years now. Recently I thought the blades needed sharpening, but instead I discovered the blade assembly could be replaced. Earlier this week the blades arrived. I used pliers to remove the tight caps holding the blade in the device, and quickly slipped the new blades into place. I have a photo of the hair which came off my boy MacDuff when I groomed him a second time, using the new blades.Wonderful. The look of cut hair (from the last use with the dull blades) disappeared and he now looks cooler and thinner. Such a LOT of hair, he has a very dense coat.I have also his sister Bella to groom with the new sharper blades. And I ordered another complete Mars Coat King with the 12 blades, about a #10 I think according to Barbara Bird’s videos of grooming pet Cairn terriers (on YouTube). I highly recommend the Mars Coat King product.